Directed Self-Assembly of Nanoparticles under Electric Fields

We develop an experimental and theoretical approach to study the effect of electric bias on particle-coverage densities produced during nanoparticle self-assembly. Experimentally, we utilize a parallel plate capacitor to allow for the application of a uniform external electric field during the self-assembly of SiO₂ nanoparticles on glass slides. We refer to this procedure as directed self-assembly of monolayers (DSAM). To determine particle-coverage densities, we use scanning electron microscopy. In our theoretical analysis, we modify existing cooperative sequential adsorption models to account for diffusion under an applied electric field. We then apply the mean field approximation to these modified models to obtain master equations, which we solve for particle-coverage densities. To ascertain the validity of these models, we compare computer simulations produced using our theoretical approach to our experimental data.